1. Field of the Invention
The present invention relates to the field of compositions devices, systems and methods for removal, in whole or in part, of undesired odors, pollutants or toxins.
2. Description of Related Art
Since mankind first became aware of the importance of hygiene, the use of antiseptics, sterilization techniques and other similar cares, the issue of malodors, and their potential adverse effects on health and quality of life have been a concern. Bad odors are sometimes an indicator of danger, such as in the case of decay where they can alert one to the possibility of infection or lurking disease. As often as not however, repugnant odors are little more than an unpleasant experience. As such they may not always be indicative of a potential health risk, but rather negatively effect quality of life. Thus, for both nuisance and health reasons, methods have been sought to eliminate or substantially alleviate bad odor experiences wherever they are encountered.
To that end, many devices and techniques have evolved through time to cope with the malodor experience. Such methods or techniques have included masking odors with perfumes, displacing odors with fans or blowers, using activated carbon as malodor absorbers, using electrostatic precipitators, candles, incense and the like. These methods and devices, though somewhat effective in lessening the impact of malodors, do not actually eliminate the malodorous substances themselves.
For example, in the case of activated carbon, malodorants are not changed and may in fact be desorbed as a result of temperature fluctuations or interior carbon particle saturation—thus rendering the method less than optimally effective. This is because the mechanism involved, which entails three separate processes (condensation, Van der Waals attraction and capillary action to the carbon particle interior), leaves the malodorous substances intact. Scrutiny of other traditional methods reveals they too leave the undesired substances intact. In electrostatic precipitation for instance, one sees a process that is fundamentally a flocculation of charged dust particles that are collected at a second stage. However, odor removal with this technique requires adsorption of noxious matter onto the targeted dust particles. This approach is clearly limited by the volatility and adsorbing propensity of the molecules involved. In any case, the odoriferous materials are not converted to less offensive compounds. Similarly, displacement and perfume masking techniques also leave the offending substances unchanged.
Recently, a fundamentally new approach to odor control has been described by the present inventors in U.S. Pat. No. 6,528,014. This “head on” approach uses chemical conversion as the mechanism by which the malodors are rendered innocuous. Certain aspects of the technology described in this patent contrast to the traditional techniques for odor control described above, as it substantially eliminates malodorous substances to benign materials by chemical conversion of the noxious particles or molecules themselves. Additionally, the technology described in U.S. Pat. No. 6,528,014 is shown to be enhanced by the use of substances called “promoters.” Appropriate promoters were described as being water-soluble ethylene oxide or propylene oxide derivatives, or mixtures of such.
While the technology of U.S. Pat. No. 6,528,014 is superior over its prior art, it is not as easily adapted as would be desirable in all circumstances to mitigate odors or other contaminants. Thus, there remains a need for compositions, systems and methods that efficiently remove odors or other contaminants from the air and from surfaces.